Resolving version conflict between java and javac on Ubuntu

Question

I have a problem with my compiled Java application on Ubuntu. It throws UnsupportedClassVersionError. I am compiling with a higher JDK version than the one that is

Answer 1

I have added and installed alternatives for Java and Javac with below steps it work for me :

Steps 1: Add the Java and Javac alternatives :

Command to add Javac:

sudo update-alternatives --install "/usr/bin/java" "java" "/opt/amazon-jdk-11/bin/java" 1 

i.e : "/opt/amazon-jdk-11/bin/javac" this the new path of java

sudo update-alternatives --install "/usr/bin/javac" "javac" "/opt/amazon-jdk-11/bin/javac" 1

i.e : /opt/amazon-jdk-11/bin/javac is the new path of javac

Steps 2: Installed the Java and Javac alternatives :

sudo update-alternatives --config javac
sudo update-alternatives --config javac

Once you enter above command you will able to see screen like below you can select your number that you want to configure java.

I have selected " 1 "int the list as I wanted to installed "/opt/amazon-jdk-11/bin/java" as my javac.

Verify your Java alternative installation is successful or not with below commands :

which javac and which java you will able to see screen like below :